In general, the image quality of a silver halide photographic material is determined by sharpness and granularity. That is, higher sharpness and better granularity are the most important properties to be achieved for an image-recording material.
Silver halide photographic materials can be divided into two groups. One is a material such as the conventional light-sensitive materials for cameras in which a light-sensitive silver halide emulsion layer or layers are provided on only one side of a support, and the other is a material such as a direct medical X-ray film in which a light-sensitive silver halide emulsion layer or layers are provided on both sides of a support.
The important factor responsible for deterioration of the sharpness of a silver halide photographic material is halation, which involves the reaction (e.g., from the surface of the film support) of light which has passed through an emulsion layer back into the emulsion layer. In order to prevent this halation, an antihalation layer is usually provided in the light-sensitive materials for cameras.
Even in the direct medical X-ray films, so-called cross-over light (other than the halation) is another important factor tending to deteriorate sharpness. In order to decrease cross-over light, a layer similar to an antihalation layer can be provided, as disclosed in U.S. Pat. No. 4,130,428 and British Pat. No. 821,352. Heretofore, as a layer for use for the above purpose, a method of using an immobile mordant and a dye has been known. This method, however, produces various problems, such as a reduction in photographic sensitivity and an increase in the fog level, due to the transfer to adjacent layers of such dyes and mordant at the time of coating or during storage.